Conventionally, a power conversion device is proposed which includes a current detection section for directly or indirectly detecting current taken from an inverter, and a current suppression section for reducing output current of the inverter when the current detected by the current detection section is higher than a set value, and thereby, in an autonomous operation performed when, for example, power supply from a power supply system has stopped, enables operation to be performed even when a cleaner or the like which is likely to cause inrush current or a lagging load is connected (for example, see Patent Document 1).
Another conventional power conversion device includes: comparison means for detecting that output of current detection means for detecting current of an inverter has exceeded a predetermined value to cause overcurrent; overcurrent control means for reducing output current of the inverter in response to the detection of overcurrent by the comparison means; and means for switching a semiconductor switch for feeding power from a power grid to a load, to a conductive state, in response to the detection of overcurrent by the comparison means, whereby, even if the conversion device becomes an overload state, shortage power is supplied from the power grid. Thus, an uninterruptible power supply device is realized which is capable of, even when short-time overcurrent occurs within one cycle of output voltage, continuing to supply power to the load without causing the conversion device to fail or stop for protection and without causing reduction or instantaneous interruption of output voltage (for example, see Patent Document 2).